I Went To Bathroomand Peed ...no Blood In Toilet,but When

I went to bathroomand peed ...no blood in toilet,but when I wiped myself I had a lot of blood on toilet tissue .I also take nexium for acid reflux as there has been a lot of controversy about getting interstitial nephritis.What could this be ?I also burn a lot sometimeswhen I start to pee and also if I am just sitting around.Thank you kindly for your response.